In order to enhance the effects of treatment, nebulizers which are used in treatment of respiratory system diseases are required to have performance to allow a drug solution to efficiently reach a target affected area. When the particle diameter of a drug solution to be nebulized is decreased, it becomes possible for particles of the drug solution to reach the bronchi, the bronchioles located back thereof, and further the alveoli. In addition, the effects of treatment can be enhanced by ensuring a sufficient nebulized amount. Accordingly, in order to improve the performance of the nebulizer, it is necessary to decrease the particle diameter of the drug solution to be nebulized from the nebulizer and to increase the nebulized amount.
An electroforming method has conventionally been used for hole processing of a nebulizer mesh (for example, see Patent Documents 1 and 2). The hole processing of the nebulizer mesh using the conventional electroforming method is described based on FIGS. 5(a) to 5(e).
FIG. 5 shows cross-sectional views for illustrating steps of obtaining the nebulizer mesh by applying thick electroplating onto a Cu substrate as a matrix. First, as shown in FIG. 5(a), a matrix 51 is prepared. The matrix 51 includes, for example, a Cu substrate. Then, as shown in FIG. 5(b), a resist pattern 52 is formed in a predetermined shape on the matrix 51. The shape thereof is, for example, circular.
Subsequently, as shown in FIG. 5(c), for example, thick electroplating using platinum as a main component is performed to deposit an electroformed film 53. The electroformed film 53 is initially deposited on a portion of the matrix 51 which is not covered with the resist pattern 52, and grows only in a direction perpendicular to a plane of the matrix 51 (in a longitudinal direction). However, when the thickness of the electroformed film 53 reaches the thickness of the resist pattern 52 or more, the electroformed film 53 grows also in a direction parallel to the plane of the matrix 51 (in a lateral direction).
Thereafter, when the thick electroplating is stopped before the resist pattern 52 is completely covered with the electroformed film 53, the electroformed film 53 as shown in FIG. 5(c) is obtained. Then, as shown in FIGS. 5(d) and 5(e), the matrix 51 and the resist pattern 52 are separated to obtain the nebulizer mesh.